The present invention relates to a radar sensor for a motor vehicle, with at least one antenna arrangement for transmitting and receiving radar signals and a controller configured for controlling operation of the antenna arrangement and for evaluating the received radar signals. In addition, the invention relates to a motor vehicle and a communication method.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Radar sensors, also for use in motor vehicles, are known in the art. In this case, radar signals are emitted, and reflected radar signals are received again by usually dedicated antennas of an antenna arrangement, so that the signals can be evaluated by evaluation logic, which may be provided in the radar sensor itself in form of a controller, for example, to detect other objects within the detection range of the radar sensor, as well as their speed by considering frequency differences and phase differences. Other evaluation methods are also possible, especially relating to an evaluation of a potentially dangerous situation, such as the risk of a collision, allowing safety systems of the vehicle to be controlled directly by the radar sensor.
Safety systems, in particular collision avoidance systems, have already been proposed in the prior art. The focus is hereby usually on the vehicle having the safety system, whereas other participating road users are also less involved in the driving process in critical traffic situations. However, the probability for a collision can be reduced dramatically, especially in extremely critical situations, when all involved road users are informed or warned about the risk. It has been proposed in this context to use car-to-car communication (car2car-communication or c2c-communication) to for example exchange information about a dangerous situation or other data.
Safety systems, in particular collision avoidance systems, frequently use radar sensors to monitor the surroundings and to derive therefrom, for example, probabilities for a collision and the like. For example, when a radar sensor of a first vehicle detects a second motor vehicle in a critical traffic situation, the second vehicle is initially tracked by the sensor for a certain time. When the second vehicle becomes critical, for example, when a collision probability threshold is exceeded, it is conceivable to inform the second vehicle via the car-to-car communication. An appropriate message is then provided by the radar sensor to a bus system of the first motor vehicle, which is configured to cause, on one hand, a warning and/or to trigger driving interventions in the first motor vehicle and, on the other hand, to reach a communication device for the car-to-car communication, where the information is converted into a message which is sent to the second motor vehicle. The second vehicle receives the danger-related information via its communication device, processes the information accordingly and transmits the information to its own bus system, which can accordingly initiate warnings and/or driving interventions.
Whereas the time window until a collision are usually very narrow in critical situations, it is evident that the described procedure may take quite some time before the actuator or the driver of the second vehicle can react, making it almost impossible to avoid an accident. Precious seconds can pass as a result of the detection, processing and transmission that would be critical for collision avoidance. Another disadvantage of the conventional solution is the complex and expensive hardware.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved method and system for supplying another vehicle more quickly with data, in particular information about dangerous situations, while at the same time reducing the hardware complexity and the cost.